Triatoma brasiliensis species complex: characterization of the external female genitalia

Abstract

The Triatoma brasiliensis complex is composed of six species (Triatoma bahiensis, T. juazerensis, T. lenti, T. melanica, T. petrocchiae, and T. sherlocki) and two subspecies (T. brasiliensis brasiliensis and T. b. macromelasoma). Phylogenetic studies have shown that it is a monophyletic group, but the morphological relationships among the members can be better understood. We applied a tool of high resolution based on morphology to identify details that characterize the female genitals for each member of this group. The external genital structures of five to fifteen females of each taxon were analyzed. Insects had their abdomen transversely cut to separate the last abdominal segments, and representative illustrations obtained via scanning electron microscopy (SEM) are shown. Observations were performed in the dorsal and the ventral views. The morphological characterization of female external genitalia allowed a differentiation of each species/subspecies. The subspecies T. b. brasiliensis and T. b. macromelasoma were the most similar. On the other hand, dorsal view of structures evidenced some unique characteristics for T. petrocchiae and T. sherlocki. Regarding these structures for T. petrocchiae, the differentiation was in accordance with molecular studies, since this species exhibits the highest genetic distances in relation to other species of T. brasiliensis complex.

External female genitalia of Triatoma jatai, Triatoma costalimai and Triatoma williami (Hemiptera: Reduviidae: Triatominae)

“…Comparative morphology studies of triatomines, including similar species of the genera Rhodnius , Triatoma , Panstrongylus and Meccus [ 6 , 18 – 23 ] have demonstrated the importance of this methodology as a complementary approach in relation to the method for identification of triatomines [ 3 ]. This approach was also used for cryptic species that are part of the Brasiliensis complex allowing differentiation between them [ 24 ].…”

Revisiting the Hybridization Processes in the Triatoma brasiliensis Complex (Hemiptera, Triatominae): Reproductive Isolation between Triatoma petrocchiae and T. b. brasiliensis and T. lenti

“…These results point to the possible presence of a prezygotic reproductive barrier due to ecological isolation between T. petrocchiae and members of the T. brasiliensis complex. However, other possible prezygotic barriers cannot be ruled out, such as mechanical isolation, as the morphological analysis of the external female genitalia evidenced some unique characteristics for T. petrocchiae [44].…”

Trends in Taxonomy of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae): From Linnaean to Integrative Taxonomy

“…Studies with OM and SEM allow characterizing structures of the head, thorax, and abdomen. These analyses are very important for classical taxonomy and support the main dichotomous keys used for the correct identification of these vectors [101,[167][168][169][170][171][172].…”